Postural abnormalities can exhibit a variety of undesirable symptoms, such as, for example, low back pain, spinal curvature, scoliosis, arthrosis, spinal disc degeneration, organ displacement, and hip and knee joint degeneration. And, it is well known that spinal misalignment can result in the appearance of undesirable and uncomfortable symptoms at locations throughout the body and limbs.
Because of the variety of postural abnormalities that can be experienced by human subjects, accurate analysis and diagnosis is required if a correct and effective treatment is to be rendered.
Skilled physicians often can perform diagnosis of postural deformities by visual observation of the subject. This is particularly true when the skeletal asymmetries are prominent.
However, in the case of slight postural abnormalities, visual inspection may lead to an incorrect diagnosis or complete failure to detect the abnormality.
So, over time, a number of different techniques and pieces of apparatus have been put forth to assist the physician in making his diagnosis. Most of these have involved measuring the relative position of various palpable landmarks on the subject's body.
The simplest diagnostic apparatus usually takes the form of a rectangular frame with fixed or movable grid lines stretched across it. Displacement of the landmarks on the subject are more apparent when the subject is viewed through the grid. One such instrument, namely the SAM spinal analysis machine produced by S.A.M. of Las Vegas, Nev., also includes a mechanical leveling platform for measuring leg length differences.
A somewhat more sophisticated apparatus for measuring short leg syndrome and consequential postural abnormalities is represented by the Dynatronic Equalizer brand analysis machine produced by Dynatronics of Salt Lake City, Utah. This device couples the grid frame with a motorized weight balance platform and digital readouts.
Faro Medical Technologies, Montreal, Canada, produces a skeletal analysis system under the trademark "METRECOM" which employs a digitizer to measure the position of a point, or group of points, on the applicant's body in three-dimensional space. The digitizer includes a plurality of rotatable transducers and a plurality of link members linking the transducers. Movement of a tip at the free end of the digitizer causes the transducers to generate signals which are transmitted to and analyzed by a computer. Operation of this apparatus is described in U.S. Pat. No. 4,571,834, granted Feb. 25, 1986, to G. A. Fraser, et. al., for "Knee Laxity Evaluation and Motion Module/Digitizer Arrangement", and U.S. Pat. No. 4,760,851, granted Aug. 2, 1988, to G. A. Fraser, et. al., for "Three-Dimensional Digitizer for Skeletal Analysis".
U.S. Pat. No. 4,922,925, granted May 8, 1990, to R. E. Crandall, et. al., for "Computer Based Upper Extremity Evaluation System" discloses a similar system for evaluation of the performance of the joints of the hand, the wrist, and the elbow.
One problem associated with the four machine techniques described above is that the subject must remain absolutely motionless during the examination. And, this is difficult for most subjects. Only a skilled operator acting swiftly is likely to produce reliable data that is useful as a basis for diagnosis.
European patent application Serial No. 87304069.5, published Nov. 11, 1987, as Publication No. 0 245 098 A2 for Teijim Limited of Osaka, Japan, discloses the use of a digitizer board for extracting positional data from an X-ray image of vertebrae. The digitized data is fed to a computer for analysis. X-rays are invasive and many subjects prefer not to be subjected to X-rays.
It has also been proposed to employ video systems for the analysis of postural abnormalities of human subjects. Representative of this art are U.S. Pat. No. 4,600,012, granted July 15, 1986, to Y. Kohayakawa, et. al., for "Apparatus for Detecting Abnormality in Spinal Column" and U.S. Pat. No. 4,699,156, granted Oct. 13, 1987, to S. Gracovetsky for "Non-invasive Method and Equipment for the Detection of Torsional Injuries in the Human Spine of a Patient". The diagnosis performed by the apparatus of the Kohayakawa patent is based solely on measuring the difference in heights of the right and left shoulders of the subject and is of only limited value in determining the treatment required. The diagnosis proposed in the Gracovetsky patent is also of limited value because it is concerned only with measuring the position of vertebrae of the lumbar curve.
Video techniques have also been employed in podiatric diagnoses, as evidenced by U.S. Pat. No. 4,416,293, granted Nov. 22, 1983, to B. V. Anderson, et. al. for "Method and Apparatus for Recording Gait Analysis in Podiatric Diagnosis and Treatment" and in weight loss/gain evaluation as disclosed in U.S. Pat. No. 4,602,280, granted July 22, 1986, to L. G. Maloomian for "Weight and/or Measurement Reduction Preview System". Neither of these techniques is capable of performing a comprehensive evaluation of postural abnormalities.
There continues to be a need for apparatus and a method for non-invasive evaluation of postural abnormalities giving reliable diagnostic results.